COATING MATERIAL FOR ALUMINUM FIN

PURPOSE:To obtain a coating material having excellent hydrophilic properties, anticorrosiveness, and processability without using any synthetic silica, by mixing a water-soluble resin and either an alkali metal zirconium carbonate or ammonium zirconium carbonate, each in a specified amount, and water. CONSTITUTION:A coating material which comprises water, a water-soluble resin, and either an alkali metal zirconium carbonate or ammonium zirconium carbonate in an amount of 20-300pts.wt. (on a ZrO2 basis) based on 100pts.wt. water-soluble resin, with the water-soluble resin content being at least 8g/l. This water-soluble resin is incorporated into a coating material for obtaining a coating film with sufficient hydrophilic properties on the surface of an aluminum fin and comprises preferably a vinyl alcohol polymer from the viewpoint of, e.g., the hardness of a film formed therefrom. An alkali metal zirconium carbonate or ammonium zirconium carbonate acts as a crosslinking agent to insolubilize the water-soluble resin so that it contributes to the corrosion resistance of an aluminum base.